Coating compositions for polymeric roofing materials

ABSTRACT

A latex emulsion may include an aqueous carrier liquid and a latex copolymer formed from reactants comprising butyl methacrylate, wherein the reactants include at least 20 wt. % butyl methacrylate, based on the total weight of ethylenically unsaturated monomers used to make the latex copolymer. A coating formed from the latex emulsion exhibits a wet adhesion to a thermoplastic polyolefin roofing membrane of greater than about 1 pound per linear inch when tested using fabric embedded peel adhesion testing per ASTM C794. The latex emulsion may be used as part of an aqueous coating composition or a roofing system including a polymeric roofing membrane.

PRIORITY CLAIM

This application claims the benefit of U.S. Application No. 62/657,530,filed Apr. 13, 2018, the contents of which are hereby incorporated byreference in their entirety.

BACKGROUND

Polymeric membranes, such as, for example, thermoplastic polyolefin(TPO) membranes, ethylene propylene diene monomer (EPDM) rubbermembranes, and poly(vinyl chloride) (PVC) membranes, are widely used ascoverings for roof surfaces of buildings. TPO, EPDM rubber, and PVCmembranes may be installed as white, single-ply membranes to provide asolar reflective surface which saves money on energy costs related tocooling the building. TPO, EPDM rubber, and PVC membranes may be coated,such as to extend the life of a new TPO, EPDM, or PVC rubber membrane orto repair damaged or worn areas of aged TPO, EPDM rubber, or PVCmembranes.

As TPO membranes age, the exposed surface of the membranes oxidizes,which may improve adhesion of coatings to the membrane. However,membranes weather differently in different climates and may weatherunevenly, e.g., due to uneven exposure to the elements.

Coatings currently used for polymeric roofing membranes are based ontwo-component epoxies, which may include high volatile organic content(VOC), relatively high cost, relatively short potlife, and relativelydifficult handling due to the requirement of mixing the two componentsprior to coating application. In many implementations, the epoxy coatingis used as a base layer or primer and topcoated with a flexible acrylicor silicone coating.

SUMMARY

In some examples, the disclosure describes a latex emulsion including anaqueous carrier liquid and a latex copolymer formed from reactantscomprising butyl methacrylate, 2-ethylhexyl methacrylate, VeoVa™ 10, orcombinations thereof, wherein the reactants include at least 20 weightpercent (wt. %) of the butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. Acoating formed from the latex emulsion optionally and preferablyexhibits a wet adhesion to a thermoplastic polyolefin roofing membraneof greater than about 1 pound per linear inch (about 0.1785 kilogramsper linear centimeter) when tested using fabric embedded peel adhesiontesting per ASTM C794 at a coat weight of about 80 ft²/gal.

In some examples, the disclosure describes an aqueous roof coatingcomposition including an aqueous carrier liquid; a dispersant, abiocide, a fungicide, an UV stabilizer, a thickener, a wetting agent, adefoamer, a filler, a pigment or colorant, or combinations thereof; anda latex copolymer formed from reactants comprising a vinyl monomerhaving an alkyl group including between 2 and 20 carbon atoms, whereinthe reactants comprise at least 20 wt. % of the vinyl monomer having analkyl group including between 2 and 12 carbon atoms, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer, and wherein a homopolymer formed from the vinyl monomerexhibits a glass transition temperature of between about −10° C. andabout 30° C. A coating formed from the coating composition optionallyand preferably exhibits a wet adhesion to a thermoplastic polyolefinroofing membrane of greater than about 1 pounds per linear inch (about0.1785 kilograms per linear centimeter) when tested using fabricembedded peel adhesion testing per ASTM C794 at a coverage of about 80ft²/gallon.

In some examples, the disclosure describes a method including reactingreactants including a vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms to form a latex emulsion including a latexcopolymer, wherein the reactants comprise at least 20 wt. % of the vinylmonomer having an alkyl group including between 2 and 20 carbon atoms,based on the total weight of ethylenically unsaturated monomers used tomake the latex copolymer, wherein a homopolymer formed from the vinylmonomer exhibits a glass transition temperature of between about −10° C.and about 30° C., and wherein a coating formed from the latex emulsionoptionally and preferably exhibits a wet adhesion to a thermoplasticpolyolefin roofing membrane of greater than about 1 pound per linearinch (about 0.1785 kilograms per linear centimeter) when tested usingfabric embedded peel adhesion testing per ASTM C794 at a coverage ofabout 80 ft²/gallon.

In some examples, the disclosure describes a roofing product thatincludes a polymeric roofing membrane and a coating on a surface of thepolymeric roofing membrane. The coating may be formed from any of thelatex emulsions described herein.

In some examples, the disclosure describes a roofing product thatincludes a polymeric roofing membrane and a coating on a surface of thepolymeric roofing membrane. The coating may be formed from any of theaqueous roof coating compositions described herein.

In some examples, the disclosure describes a method including coating apolymeric roofing membrane with a coating formed from a latex emulsionincluding an aqueous carrier liquid and a latex copolymer formed fromreactants comprising butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, wherein the reactants include atleast 20 wt. % of the butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. Thecoating optionally and preferably exhibits a wet adhesion to athermoplastic polyolefin roofing membrane of greater than about 1 poundper linear inch (about 0.1785 kilograms per linear centimeter) whentested using fabric embedded peel adhesion testing per ASTM C794 at acoverage of about 80 ft²/gallon.

In some examples, the disclosure describes a method including coating apolymeric roofing membrane with a coating formed from an aqueous roofcoating composition including an aqueous carrier liquid; a dispersant, abiocide, a fungicide, an UV stabilizer, a thickener, a wetting agent, adefoamer, a filler, a pigment or colorant, or combinations thereof; anda latex copolymer formed from reactants comprising a vinyl monomerhaving an alkyl group including between 2 and 20 carbon atoms, whereinthe reactants comprise at least 20 wt. % of the vinyl monomer having analkyl group including between 2 and 20 carbon atoms, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer, and wherein a homopolymer formed from the vinyl monomerexhibits a glass transition temperature of between about −10° C. andabout 30° C. A coating formed from the coating composition optionallyand preferably exhibits a wet adhesion to a thermoplastic polyolefinroofing membrane of greater than about 1 pounds per linear inch (about0.1785 kilograms per linear centimeter) when tested using fabricembedded peel adhesion testing per ASTM C794 at a coverage of about 80ft²/gallon.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages of the disclosure will be apparent from the description anddrawings, and from the claims.

DETAILED DESCRIPTION

A “latex” polymer means a dispersion or emulsion of polymer particlesformed in the presence of water and one or more dispersing oremulsifying agents (e.g., a surfactant, alkali-soluble polymer, ormixtures thereof) whose presence is required to form the dispersion oremulsion. The dispersing or emulsifying agent is typically separate fromthe polymer after polymer formation. In some examples, a reactivedispersing or emulsifying agent may become part of the polymer particlesas they are formed.

The recitation of a numerical range using endpoints includes all numberssubsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4, 5, etc.).

The terms “a,” “an,” “the,” “at least one,” and “one or more” are usedinterchangeably. Thus, for example, a coating composition that contains“an” additive means that the coating composition includes “one or more”additives.

The phrase “low VOC” when used with respect to a liquid coatingcomposition means that the liquid coating composition contains less thanabout 150 grams VOC per L composition, excluding water weight (g VOC/Lcomposition; about 15% w/v) by U.S.A. EPA Method 24, preferably not morethan about 100 g VOC/L composition (about 10% w/v), more preferably notmore than about 50 g VOC/L composition (about 5% w/v), and mostpreferably less than 20 g VOC/L composition (about 2% w/v), for examplenot more than about 10 g VOC/L composition (about 1% w/v) or not morethan about 8 g VOC/L composition (about 0.8% w/v) volatile organiccompounds.

The term “(meth)acrylic acid” includes either or both of acrylic acidand methacrylic acid, and the term “(meth)acrylate” includes either orboth of an acrylate and a methacrylate.

The terms “topcoat” or “final topcoat” refer to a coating compositionwhich when dried or otherwise hardened provides a decorative orprotective outermost finish layer on a substrate, for example, apolymeric membrane attached to a building exterior (e.g., a roof). Byway of further explanation, such final topcoats include paints, stainsor sealers capable of withstanding extended outdoor exposure (e.g.,exposure equivalent to one year of vertical south-facing Floridasunlight) without visually objectionable deterioration, but do notinclude primers that would not withstand extended outdoor exposure ifleft uncoated with a topcoat.

The present disclosure describes latex emulsions and aqueous coatingcompositions including latex emulsions that have relatively high wetadhesion to polymeric roofing membranes, such as TPO membranes, EPDMrubber membranes, or PVC membranes. The latex emulsions and aqueouscoating compositions may be used as primer coats or topcoats onpolymeric roofing membranes. The latex emulsion includes an aqueouscarrier liquid and a latex copolymer preferably formed from reactantsthat include a vinyl monomer having an alkyl group including at least 2carbon atoms, such as at least 3 carbon atoms, or at least 4 carbonatoms. Typically, the alkyl group including at least 2 carbons has lessthan 20 carbons, less than 15 carbons, or less than 12 carbons. In someexamples, the vinyl monomer may include an alkyl group that includesbetween 2 and 20 carbon atoms. The vinyl monomer may optionally andpreferably include(R³)₂—C═C(R⁴)—W_(n)—C(R⁵)₂—C(R⁵)₃wherein R³ is independently selected from hydrogen or an organic group(typically at least one and more typically both R³ are hydrogen atoms);R⁴ is selected from hydrogen or an alkyl group (e.g., a methyl group);W, if present, is a divalent linking group (e.g., an ester bond ofeither directionality: —C(C═O)— or —(C═O)C—); n is 0 or 1, moretypically 1; and each R⁵ is independently hydrogen, a linear alkylgroup, or a branched alkyl group. A homopolymer formed from the vinylmonomer preferably exhibits a glass transition temperature between about−10° C. and about 30° C., or between about −7° C. and about 25° C., orbetween about −7° C. and about 20° C. For example, the glass transitiontemperature of n-butyl methacrylate is about 20° C., the glasstransition temperature of VeoVa™ 10 is about −3° C., and the glasstransition temperature of 2-ethylhexyl methacrylate is about −6° C.

The value of the glass transition temperature is based on literaturevalues. Typically, there is some variation of the glass transitiontemperature values of the homopolymers of monomers listed in suchliterature. For example, the glass transition temperature of thehomopolymer of 2-ethyl hexyl acrylate has various literature values from−55° C. to −85° C. The difference arises from the test method used tomeasure the glass transition temperature. For the purposes of thisdisclosure, the values used for the homopolymer glass transitiontemperature of certain monomers, particularly monomers used in theexamples, are listed herein. Alternatively, the method of determiningthe glass transition temperature of a homopolymer can be determinedusing the DSC procedure described herein, particularly if the literaturevalues are significantly different (e.g., the literature values vary byat least 15° C.).

In some examples, the alkyl group may include one or more heteroatoms.In other examples, the alkyl group is unsubstituted. The alkyl group mayinclude or consist of a cycloalkyl, or, in some preferred examples, mayexclude a cycloalkyl group.

In some examples, the vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms may include laurel methacrylate, n-butylmethacrylate, iso-butyl methacrylate, t-butyl methacrylate, sec-butylmethacrylate, 2-ethylhexyl methacrylate, VeoVa™ 10, or combinationsthereof. VeoVa™ 10 is a monomer available from HEXION™ Inc., Columbus,Ohio, and is a vinyl ester of neodecanoic acid, a synthetic saturatedmonocarboxylic acid with a highly branched structure containing tencarbon atoms. VeoVa™ 10 is represented by the formula: —CH₂═CH₂—O—(C═O)—C(R¹)(R²)CH₃, where R¹ and R² are alkyl groups containing a total of 7carbon atoms. In some examples, the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms consists of n-butyl methacrylateor a mixture of n-butyl methacrylate and 2-ethylhexyl methacrylate.

The latex emulsion may be used to coat a substrate, such as a polymericroofing membrane including TPO, EPDM rubber, PVC, or the like, or may beused in combination with one or more additives, such as a dispersant, abiocide, a fungicide, an UV stabilizer, a thickener, a wetting agent, adefoamer, a filler, a pigment or colorant, or combinations thereof, toform an aqueous coating composition that is used to coat a substrate.The latex emulsion or aqueous coating composition may be used to formcoatings directly on polymeric roofing membranes. The coatingspreferably exhibit desirable wet adhesion, e.g., a wet adhesion tovirgin TPO of greater than about 1 pound per linear inch when testedusing fabric embedded peel adhesion testing per ASTM C794 at a coverageof about 80 ft²/gallon. In some examples, the coatings formed on virginTPO using the latex emulsion or aqueous coating composition preferablyexhibits a wet adhesion of greater than 1 pound per linear inch (about0.1785 kilograms per linear centimeter), greater than about 2 pounds perlinear inch (about 0.357 kilograms per linear centimeter) or greaterthan about 4 pounds per linear inch (about 0.714 kilograms per linearcentimeter) when tested using fabric embedded peel adhesion testing perASTM C794 at a coverage of about 80 ft²/gallon. As used herein, virginTPO is a TPO membrane that has not been subjected to aging induced byenvironmental factors such as UV light.

In this way, the latex emulsions and aqueous coating compositionsincluding the latex emulsion may be used as a primer coat or a topcoatfor polymeric roofing membranes, such as TPO membrane roofing panels,EPDM rubber membrane roofing panels, or PVC membrane roofing panels. Thelatex emulsions and aqueous coating compositions may provide one or morebenefits compared to two-component epoxies, such as lower volatileorganic content (VOC), lower cost, relatively longer potlife, orrelatively easier handling due to single component nature of the latexemulsions and aqueous coating compositions. The latex emulsions andaqueous coating compositions may be used to repair polymeric roofingmembranes and extend a useful life of the polymeric roofing membranes,coat polymeric roofing membranes to reduce aging and extend a usefullife of the polymeric roofing membranes, coat polymeric roofingmembranes to modify appearance of polymeric roofing membranes, or thelike.

The latex emulsions include an aqueous carrier liquid and a latexcopolymer. In some examples, the latex copolymer is an emulsionpolymerized latex copolymer. The reactants that form the latex copolymermay include a vinyl monomer having an alkyl group including between 2and 20 carbon atoms, preferably between 3 and 15 carbon atoms, morepreferably between 2 and 12 carbon atoms. The vinyl monomer may includeany monomer consistent with the definition and examples presented above.In some examples, the vinyl monomer includes a methacrylate. As usedherein, a methacrylate having an alkyl group including between X and Ycarbon atoms (e.g., between 2 and 20 carbon atoms) refers to amethacrylate having the following formula, where the R₂ group is thealkyl group including between X and Y carbon atoms and R₁ is a methylgroup: H₂C═C(R₁)C(═O)OR₂. The alkyl group may include a linear alkylgroup, a branched alkyl group, a cycloalkyl group, or an unsaturatedalkyl group. In some examples, the alkyl group may exclude a cycloalkylgroup. For example, the methacrylate may include or consist of laurelmethacrylate, n-butyl methacrylate, iso-butyl methacrylate, t-butylmethacrylate, sec-butyl methacrylate, 2-ethylhexyl methacrylate, or thelike, or combinations thereof. In some examples, the methacrylateincludes or consists of n-butyl methacrylate or a mixture of n-butylmethacrylate and 2-ethylhexyl methacrylate.

The reactants used to form the latex copolymer may include at least 20wt. % of the vinyl monomer having an alkyl group including between 2 and20 carbon atoms, based on the total weight of ethylenically unsaturatedmonomers used to make the latex copolymer. As used herein, “based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer” refers to a basis of the total amount of monomer usedto form the latex copolymer. In some examples, the reactants include atleast about 25 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orat least about 30 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orat least about 50 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. Insome examples, the reactants used to form the latex copolymer mayinclude less than about 99 wt. % of the vinyl monomer having an alkylgroup including between 2 and 20 carbon atoms, based on the total weightof ethylenically unsaturated monomers used to make the latex copolymer;or less than about 75 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orless than about 60 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orless than about 55 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. Insome examples, the latex copolymer includes between about 20 and about55 wt. % of the vinyl monomer having an alkyl group including between 2and 20 carbon atoms, based on the total weight of ethylenicallyunsaturated monomers used to make the latex copolymer.

In some examples, the reactants that form the latex copolymer alsoinclude an ethylenically unsaturated polar component. For example, theethylenically unsaturated polar component may include an ethylenicallyunsaturated monomer including at least one alcohol group, anethylenically unsaturated ionic monomer, an at least partiallyneutralized ethylenically unsaturated ionic monomer, or the like. The atleast partially neutralized ethylenically unsaturated ionic monomer maybe a salt form of the ethylenically unsaturated ionic monomer, and thesalt form may be formed prior to, during, or after reaction of theethylenically unsaturated ionic monomer with the other monomers in thereactants to form the latex copolymer.

In some examples, the ethylenically unsaturated polar monomer mayinclude an acid- or anhydride-functional ethylenically unsaturatedmonomer or an at least partially neutralized acid- oranhydride-functional ethylenically unsaturated monomer. For example, theethylenically unsaturated polar monomer may include acrylic acid,methacrylic acid, crotonic acid, fumaric acid, maleic acid, 2-methylmaleic acid, itaconic acid, 2-methyl itaconic acid, anhydride variantsthereof, at least partially neutralized variants thereof, orcombinations thereof.

The reactants used to form the latex copolymer may include at leastabout 0.1 wt. % of the ethylenically unsaturated polar monomer, based onthe total weight of all reactants covalently bound in the latexcopolymer. In some examples, the reactants include greater than about0.1 wt. % of the ethylenically unsaturated polar monomer, based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer; or greater than about 0.5 wt. % of the ethylenicallyunsaturated polar monomer, based on the total weight of ethylenicallyunsaturated monomers used to make the latex copolymer; or greater thanabout 1 wt. % of the ethylenically unsaturated polar monomer, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer. In some examples, the reactants include less than about10 wt. % of the ethylenically unsaturated polar monomer, based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer; or less than about 5 wt. % of the ethylenicallyunsaturated polar monomer, based on the total weight of ethylenicallyunsaturated monomers used to make the latex copolymer; or less thanabout 3 wt. % of the ethylenically unsaturated polar monomer, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

The reactants that form the latex copolymer also may include a chaintransfer agent. In some examples, the reactants include at least about0.1 wt. % of the chain transfer agent, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orat least about 0.25 wt. % of the chain transfer agent, based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer; or at least about 0.5 wt. % of the chain transferagent, based on the total weight of ethylenically unsaturated monomersused to make the latex copolymer. In some examples, the reactants mayinclude less than about 2 wt. % of the chain transfer agent, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer; or less than about 1 wt. % of the chain transfer agent,based on the total weight of ethylenically unsaturated monomers used tomake the latex copolymer; or less than about 0.75 wt. % of the chaintransfer agent, based on the total weight of ethylenically unsaturatedmonomers used to make the latex copolymer. The chain transfer agent mayinclude any suitable chain transfer agent, such as a thiol. In someexamples, the chain transfer agent includes or consists of a mercaptan,such as dodecyl mercaptan.

In some examples, the reactants optionally include another monomer.Suitable additional monomer(s) include, for example, methyl acrylate,ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,methyl methacrylate, ethyl methacrylate, propyl methacrylate,2-ethylhexyl methacrylate, hydroxyethyl acrylate, hydroxyethylmethacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, glycidylmethacrylate, 4-hydroxybutyl acrylate glycidyl ether,2-(acetoacetoxy)ethyl methacrylate (AAEM), diacetone acrylamide (DAAM),acrylamide, methacrylamide, methylol (meth)acrylamide, styrene, α-methylstyrene, vinyl toluene, vinyl acetate, vinyl propionate, allylmethacrylate, and mixtures thereof. Some preferred monomers includestyrene, methyl methacrylate, methacrylic acid, acetoacetoxy ethylmethacrylate, butyl acrylate, and the like. The additional monomer maybe selected to reduce a glass transition temperature (T_(g)) of thelatex copolymer. Thus, the additional monomer may have a homopolymerT_(g) that is less than the homopolymer T_(g) of the methacrylate havingthe alkyl group including between 2 and 20 carbon atoms. For example,the additional monomer may have a homopolymer glass transitiontemperature that is less than −25° C., or less than about −35° C., orless than about −50° C. In some implementations, the additional monomerincludes or consists of an alkyl acrylate, such as 2-ethylhexylacrylate. When present, the reactants may include at least about 10 wt.% of the additional monomer, based on the total weight of ethylenicallyunsaturated monomers used to make the latex copolymer; or at least about20 wt. % of the additional monomer, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orat least about 30 wt. % of the additional monomer, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer. In some examples, the reactants may include less than about80 wt. % of the additional monomer, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer; orless than about 60 wt. % of the additional monomer, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer; or less than about 50 wt. % of the additional monomer, basedon the total weight of ethylenically unsaturated monomers used to makethe latex copolymer.

In some examples, the reactants further include a ureido-functionalmonomer. The ureido-functional monomer may affect adhesion of the latexcopolymer to substrates, including polymeric roofing membranesubstrates. In some examples, the ureido-functional monomer includes aureido-functional ethylenically unsaturated monomer, such as aureido-functional methacrylic monomer. Example ureido-functionalethylenically unsaturated monomer include those available under thetrade designations SIPOMER® WAM and SIPOMER® WAM II available fromSolvay S.A., Brussels, Belgium, and VISIOMER® MEEU 25 M from EvonikIndustries, Essen, Germany.

In some examples, the reactants further include a seed latex. The seedlatex may function as a polymerization growth site and may affect afinal particle size of the latex copolymer

The latex copolymers disclosed above may, in some examples, be formedand/or stabilized with one or more emulsifiers (e.g., surfactants), usedeither alone or together. Examples of suitable nonionic emulsifiersinclude tert-octylphenoxyethylpoly(39)-ethoxyethanol,dodecyloxypoly(10)ethoxyethanol,nonylphenoxyethyl-poly(40)ethoxyethanol, polyethylene glycol 2000monooleate, ethoxylated castor oil, fluorinated alkyl esters andalkoxylates, polyoxyethylene (20) sorbitan monolaurate, sucrosemonococoate, di(2-butyl) phenoxypoly(20)ethoxyethanol,hydroxyethylcellulosepolybutyl acrylate graft copolymer, dimethylsilicone polyalkylene oxide graft copolymer, poly(ethyleneoxide)poly(butyl acrylate) block copolymer, block copolymers ofpropylene oxide and ethylene oxide,2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylated with ethylene oxide,N-polyoxyethylene(20)lauramide, N-lauryl-N-polyoxyethylene(3)amine andpoly(10)ethylene glycol dodecyl thioether. Examples of suitable anionicemulsifiers include sodium lauryl sulfate, sodiumdodecylbenzenesulfonate, potassium stearate, sodium dioctylsulfosuccinate, sodium dodecyldiphenyloxide disulfonate,nonylphenoxyethylpoly(1)ethoxyethyl sulfate ammonium salt, sodiumstyrene sulfonate, sodium dodecyl allyl sulfosuccinate, linseed oilfatty acid, sodium, potassium, or ammonium salts of phosphate esters ofethoxylated nonylphenol or tridecyl alcohol, sodiumoctoxynol-3-sulfonate, sodium cocoyl sarcocinate, sodium1-alkoxy-2-hydroxypropyl sulfonate, sodium alpha-olefin(C₁₄-C₁₆)sulfonate, sulfates of hydroxyalkanols, tetrasodiumN-(1,2-dicarboxy ethyl)-N-octadecylsulfosuccinamate, disodiumN-octadecylsulfosuccinamate, disodium alkylamido poly-ethoxysulfosuccinate, disodium ethoxylated nonylphenol half ester ofsulfosuccinic acid and the sodium salt oftert-octylphenoxyethoxypoly(39)ethoxyethyl sulfate.

The latex copolymer may be polymerized using chain growthpolymerization. One or more water-soluble free radical initiators may beused in the chain growth polymerization. Initiators suitable for use inthe coating compositions will be known to persons having ordinary skillin the art or can be determined using standard methods. Representativewater-soluble free radical initiators include hydrogen peroxide;tert-butyl peroxide; alkali metal persulfates such as sodium, potassiumand lithium persulfate; ammonium persulfate; and mixtures of suchinitiators with a reducing agent. Representative reducing agents includesulfites such as alkali metal metabisulfite, hydrosulfite, andhyposulfite; sodium formaldehyde sulfoxylate; and reducing sugars suchas ascorbic acid and isoascorbic acid. The amount of initiator ispreferably from about 0.01 to about 3 wt. %, based on the total weightof ethylenically unsaturated monomers used to make the latex copolymer.In a redox system the amount of reducing agent is preferably from 0.01to 3 wt. %, based on the total weight of ethylenically unsaturatedmonomers used to make the latex copolymer. The polymerization reactioncan be performed at a temperature in the range of from about 10° C. toabout 100° C.

The latex copolymer may exhibit a measured glass transition temperatureof less than about −10° C., or less than about −15° C., or less thanabout −20° C. In some examples, the latex copolymer exhibits a measuredglass transition temperature of greater than about −50° C., or greaterthan about −40° C., or greater than about −30° C. For example, the latexcopolymer may exhibit a measured glass transition temperature of betweenabout −50° C. and about −20° C. The glass transition temperature may bemeasured by air drying a sample overnight and analyzing the dried sampleon a Q2000 DSC from TA Instruments using a heat-cool-heat cycle from−75° C. to 150° C. and back at a rate of 20° C. per minute. The glasstransition temperature was measured from the midpoint of the transitionon the second heat cycle.

In some examples, the latex copolymer may include both soluble andinsoluble fractions. A gel fraction of the latex copolymer may bedetermined by soaking a sample of air-dried latex copolymer in a porousbag or pouch in a solvent, such as tetrahydrofuran (THF). The gelfraction is determined as the final weight of the sample (after drying)divided by the initial weight of the sample (after drying). A moredetailed description of a suitable methodology is provided in theexamples section. In some examples, the latex copolymer may exhibit agel fraction of between 0% and about 10%, or between 0% and about 5%, orbetween 0% and about 3.5%, or between about 1.0% and about 3.5%.

The solubilized portion of the latex copolymer from the gel fractiontest preferably exhibits a weight average molecular weight. In someexamples, the weight average molecular weight may be less than about300,000 g/mol. In other examples, the weight average molecular weightmay be less than about 230,000 g/mol or less than about 200,000 g/mol.In some examples, the weight average molecular weight may be greaterthan about 50,000 g/mol, or between about 50,000 g/mol and about 230,000g/mol, or between about 50,000 and about 200,000 g/mol.

The latex copolymer may exhibit any volume average particle size, as theaverage particle size is not believed to be important. In some examples,the latex copolymer may exhibit a volume average particle size ofbetween about 150 nm and about 550 nm. The volume average particle sizemay be determined using a Nanotrac Wave II particle size analyzer fromMicrotrac Inc., Montgomeryville, Pa.

In some examples, the latex emulsion or aqueous coating composition mayinclude a total solids content of between about 50% and about 60%, orabout 55%.

The latex emulsion may exhibit a viscosity suitable for application ofthe latex emulsion, either alone or in combination with one or moreadditives in a coating composition, to a substrate using typical coatingapplication techniques, such as rolling, brushing, dipping, spraying, orthe like.

The latex emulsion may be used to coat substrates, e.g., as a primercoat or a topcoat. For example, the latex emulsion may be used to coatpolymeric roofing membranes, such as thermoplastic polyolefin (TPO)membranes, ethylene propylene diene monomer (EPDM) rubber membranes, PVCmembranes, or the like. The polymeric roofing membranes may be used asroofing materials. The latex emulsion may be applied directly to thepolymeric roofing membrane and preferably exhibits desirable dry and wetadhesion to the polymeric roofing membrane. For example, a coatingformed from the latex emulsion preferably exhibits a wet adhesion ofgreater than about 1 pounds per linear inch, or greater than about 2pounds per linear inch, or greater than about 4 pounds per linear inchwhen tested using fabric embedded peel adhesion testing per ASTM C794 ata coverage of about 80 ft²/gallon. For the fabric embedded peel adhesiontesting, the latex emulsion was applied to the polymeric roofingmembrane at a coverage of about 80 ft²/gallon. Half of the coatingcomposition mass was brushed onto virgin TPO and a 4″ wide strip ofnon-woven polyester fabric available under the trade designation Henry296 ElastoTape® Repair Fabric from Henry Company, El Segundo, Calif. wasembedded into the coating. The remaining coating composition mass wasthen brushed onto the embedded polyester fabric. Samples were driedunder ambient conditions for 14 days. Dry adhesion was then measuredusing an MTS Insight® Electromechanical Testing System. The fabric wasgripped in one clamp of the MTS Insight® Electromechanical TestingSystem and the virgin TPO sheet in the other clip. The pulling rate was2 inches per minute and 2 inches of the samples were tested.

After dry adhesion testing, the samples were immersed in water for 7days. Wet adhesion was then tested according to ASTM C794 using an MTSInsight® Electromechanical Testing System. The fabric was gripped in oneclamp of the MTS Insight® Electromechanical Testing System and thevirgin TPO sheet in the other clip. The pulling rate was 2 inches perminute and 2 inches of the samples were tested.

In some examples, rather than being used neat to coat a substrate, thelatex emulsion may be part of an aqueous coating composition thatinclude at least one additive. The at least one additive may include,for example, a dispersant, a biocide, a fungicide, an UV stabilizer, athickener, a wetting agent, a defoamer, a filler, a pigment or colorant,or combinations thereof.

The aqueous coating composition may contain one or more optionalingredients that are or contain VOCs. Such ingredients will be known topersons having ordinary skill in the art or can be determined usingstandard methods. Desirably, the coating compositions are low VOC, andpreferably include not more than 150 g VOC/L composition, excludingwater weight (about 15% w/v) by U.S.A. EPA Method 24, preferably notmore than about 100 g VOC/L composition (about 10% w/v), more preferablynot more than about 50 g VOC/L composition (about 5% w/v), and mostpreferably not more than 20 g VOC/L composition (about 2% w/v), forexample not more than about 10 g VOC/L composition (about 1% w/v) or notmore than about 8 g VOC/L composition (about 0.8% w/v) volatile organiccompounds.

The aqueous coating composition may contain one or more optionalcoalescents to facilitate film formation. Coalescents suitable for usein the coating compositions will be known to persons having ordinaryskill in the art or can be determined using standard methods. Exemplarycoalescents include glycol ethers such those sold under the trade namesas EASTMAN™ EP, EASTMAN™ DM, EASTMAN™ DE, EASTMAN™ DP, EASTMAN™ DB andEASTMAN™ PM from Eastman Chemical Company, Kingsport, Tenn., and esteralcohols such as those sold under the trade names TEXANOL™ ester alcoholfrom Eastman Chemical Company. The optional coalescent may be a low VOCcoalescent such as is described in U.S. Pat. No. 6,762,230 B2. Thecoating compositions may include a low VOC coalescent in an amount of atleast about 0.5 wt. %, or at least about 1 part by weight, and or atleast about 2 wt. %, based on a total non-volatile weight of the latexcopolymer. The coating compositions also may include a low VOCcoalescent in an amount of less than about 10 wt. %, or less than about6 wt. %, or less than about 4 wt. %, based on a total non-volatileweight of the latex copolymer.

Other optional additives for use in the aqueous coating compositionsherein are described in Koleske et al., Paint and Coatings Industry,April, 2003, pages 12-86. Some performance enhancing additives that mayoptionally be employed include coalescing solvent(s), defoamers,dispersants, amines, preservatives, biocides, mildewcides, fungicides,glycols, surface active agents, pigments, colorants, dyes, surfactants,thickeners, heat stabilizers, leveling agents, anti-cratering agents,curing indicators, plasticizers, fillers, sedimentation inhibitors,ultraviolet-light absorbers, optical brighteners, external crosslinkers,and the like to modify properties of the aqueous coating composition.

The disclosed coating compositions may include a surface-active agent(e.g., surfactant) that modifies the interaction of the coatingcomposition with the substrate or with a prior applied coating. Thesurface-active agent affects qualities of the aqueous coatingcomposition including how the aqueous coating composition is handled,how it spreads across the surface of the substrate, and how it bonds tothe substrate. The surface-active agent can modify the ability of theaqueous coating composition to wet a substrate and also may be referredto as a wetting agent. Surface-active agents may also provide leveling,defoaming, or flow control properties, and the like. If the aqueouscoating composition includes a surface-active agent, the surface-activeagent is preferably present in an amount of less than 5 wt. %, based onthe total weight of the aqueous coating composition. Surface-activeagents suitable for use in the coating composition will be known topersons having ordinary skill in the art or can be determined usingstandard methods. Some suitable surface-active agents include thoseavailable under the trade designations STRODEX™ KK-95H, STRODEX™ PLF100,STRODEX™ PKOVOC, STRODEX™ LFK70, STRODEX™ SEK50D and DEXTROL™ 0050 fromDexter Chemical L.L.C., Bronx, N.Y.; HYDROPALAT™ 100, HYDROPALAT™ 140,HYDROPALAT™ 44, HYDROPALAT™ 5040 and HYDROPALAT™ 3204 from CognisCorporation, Cincinnati, Ohio; LIPOLIN™ A, DISPERS™ 660C, DISPERS™ 715Wand DISPERS™ 750W from Degussa Corporation, Parsippany, N.J.; BYK™ 156,BYK™ 2001 and ANTI-TERRA™ 207 from Byk Chemie, Wallingford, Conn.;DISPEX™ A40, DISPEX™ N40, DISPEX™ R50, DISPEX™ G40, DISPEX™ GA40, EFKA™1500, EFKA™ 1501, EFKA™ 1502, EFKA™ 1503, EFKA™ 3034, EFKA™ 3522, EFKA™3580, EFKA™ 3772, EFKA™ 4500, EFKA™ 4510, EFKA™ 4520, EFKA™ 4530, EFKA™4540, EFKA™ 4550, EFKA™ 4560, EFKA™ 4570, EFKA™ 6220, EFKA™ 6225, EFKA™6230 and EFKA™ 6525 from Ciba Specialty Chemicals, Tarrytown, N.Y.;SURFYNOL™ CT-111, SURFYNOL™ CT-121, SURFYNOL™ CT-131, SURFYNOL™ CT-211,SURFYNOL™ CT 231, SURFYNOL™ CT-136, SURFYNOL™ CT-151, SURFYNOL™ CT-171,SURFYNOL™ CT-234, CARBOWET™ DC-01, SURFYNOL™ 104, SURFYNOL™ PSA-336,SURFYNOL™ 420, SURFYNOL™ 440, ENVIROGEM™ AD-01 and ENVIROGEM AE01 fromAir Products & Chemicals, Inc., Allentown, Pa.; TAMOL™ 1124, TAMOL 850,TAMOL 681, TAMOL™ 731 and TAMOL™ SG-1 from Rohm and Haas Co.,Philadelphia, Pa.; IGEPAL™ CO-210, IGEPAL™ CO-430, IGEPAL™ CO-630,IGEPAL™ CO-730, and IGEPAL™ CO-890 from Rhodia Inc., Cranbury, N.J.;T-DET™ and T-MULZ™ products from Harcros Chemicals Inc., Kansas City,Kans.; polydimethylsiloxane surface-active agents (such as thoseavailable under the trade designations SILWET™ L-760 and SILWET™ L-7622from OSI Specialties, South Charleston, W.Va., or BYK™ 306 fromByk-Chemie) and fluorinated surface-active agents (such as thatcommercially available as FLUORAD™ FC-430 from 3M Co., St. Paul, Minn.).

In some examples, the surface-active agent may be a defoamer. Somesuitable defoamers include those sold under the trade names BYK™ 018,BYK™ 019, BYK™ 020, BYK™ 022, BYK™ 025, BYK™ 032, BYK™ 033, BYK™ 034,BYK™ 038, BYK™ 040, BYK™ 051, BYK™ 060, BYK™ 070, BYK™ 077 and BYK™ 500from Byk Chemie; SURFYNOL™ DF-695, SURFYNOL™ DF-75, SURFYNOL™ DF-62,SURFYNOL™ DF-40 and SURFYNOL™ DF-110D from Air Products & Chemicals,Inc.; DEEFO™ 3010A, DEEFO™ 2020E/50, DEEFO™ 215, DEEFO™ 806-102 andAGITAN™ 31BP from Munzing Chemie GmbH, Heilbronn, Germany; EFKA 2526,EFKA 2527 and EFKA 2550 from Ciba Specialty Chemicals; FOAMAX™ 8050,FOAMAX™ 1488, FOAMAX™ 7447, FOAMAX™ 800, FOAMAX™ 1495 and FOAMAX 810from Degussa Corp.; FOAMASTER™ 714, FOAMASTER™ A410, FOAMASTER™ 111,FOAMASTER™ 333, FOAMASTER™ 306, FOAMASTER™ SA-3, FOAMASTER™ AP,DEHYDRAN™ 1620, DEHYDRAN™ 1923 and DEHYDRAN™ 671 from Cognis Corp.

The aqueous coating composition also may contain one or more optionalexternal crosslinkers. External crosslinkers may improve tensilestrength of a coating formed from the aqueous coating composition.Example external crosslinkers include silanes, zinc oxide pigments,nanozinc, ZINPLEX 15 (available from Munzing, Bloomfield, N.J.), and thelike.

The aqueous coating composition also may contain one or more optionalpigments. Pigments suitable for use in the coating compositions will beknown to persons having ordinary skill in the art or can be determinedusing standard methods. Some suitable pigments include titanium dioxidewhite, carbon black, lampblack, black iron oxide, red iron oxide, yellowiron oxide, brown iron oxide (a blend of red and yellow oxide withblack), phthalocyanine green, phthalocyanine blue, organic reds (such asnaphthol red, quinacridone red and toulidine red), quinacridone magenta,quinacridone violet, DNA orange, or organic yellows (such as Hansayellow). The aqueous coating composition can also include a glosscontrol additive or an optical brightener, such as that commerciallyavailable under the trade designation UVITEX™ OB from Ciba-Geigy.

In some examples, the aqueous coating composition may include anoptional filler or inert ingredient. Fillers or inert ingredientsextend, lower the cost of, alter the appearance of, or provide desirablecharacteristics to the aqueous coating composition before and aftercuring. Fillers and inert ingredients suitable for use in the aqueouscoating composition will be known to persons having ordinary skill inthe art or can be determined using standard methods. Some suitablefillers or inert ingredients include, for example, clay, glass beads,calcium carbonate, talc, silicas, feldspar, mica, barytes, ceramicmicrospheres, calcium metasilicates, organic fillers, and the like.Suitable fillers or inert ingredients are preferably present in anaggregate amount of less than about 40 wt. %, such as less than about 15wt. %, based on the total weight of the aqueous coating composition.

In certain applications it may also be desirable to include in theaqueous coating composition a biocide, fungicide, or the like. Somesuitable biocides or fungicides include those sold under the trade namesROZONE™ 2000, BUSAN™ 1292 and BUSAN 1440 from Buckman Laboratories,Memphis, Tenn.; POLYPHASE™ 663 and POLYPHASE™ 678 from Troy ChemicalCorp., Florham Park, N.J.; and KATHON™ LX from Rohm and Haas Co.

The aqueous coating composition may also include other ingredients thatmodify properties of the aqueous coating composition as it is stored,handled, or applied, and at other or subsequent stages. Waxes, flattingagents, rheology control agents, mar and abrasion additives, and othersimilar performance enhancing additives may be employed as needed inamounts effective to upgrade the performance of the cured coating andthe aqueous coating composition. Some suitable wax emulsions to improvecoating physical performance include those sold under the trade namesMICHEM™ Emulsions 32535, 21030, 61335, 80939M and 7173MOD fromMichelman, Inc. Cincinnati, Ohio and CHEMCOR™ 20N35, 43A40, 950C25 and10N30 from ChemCor of Chester, N.Y. Some suitable rheology controlagents include those sold under the trade names RHEOVIS™ 112, RHEOVIS™132, RHEOVIS™, VISCALEX™ HV30, VISCALEX™ AT88, EFKA™ 6220 and EFKA™06225 from Ciba Specialty Chemicals; BYK™ 420 and BYK™ 425 from BykChemie; RHEOLATE™ 205, RHEOLATE™ 420 and RHEOLATE™ 1 from ElementisSpecialties, Hightstown, N.J.; ACRYSOL™ L TT-615, ACRYSOL™ RM-5,ACRYSOL™ RM-6, ACRYSOL™ RM-8W, ACRYSOL™ RM-2020 and ACRYSOL™ RM-825 fromRohm and Haas Co.; NATROSOL™ 250LR from Hercules Inc., Wilmington, Del.and CELLOSIZE™ QP09L from Dow Chemical Co., Midland, Mich. Desirableperformance characteristics of the coating include adhesion, chemicalresistance, abrasion resistance, hardness, gloss, reflectivity,appearance, or combinations of these characteristics, and other similarcharacteristics. For example, the composition may include abrasionresistance promoting adjuvants such as silica or aluminum oxide (e.g.,sol gel processed aluminum oxide).

In certain applications it may also be desirable to include in theaqueous coating composition an optional UV stabilizer. Concentration ofthe optional UV stabilizer in the aqueous coating composition will beknown to persons having ordinary skill in the art or can be determinedusing standard methods. UV stabilizers may include encapsulatedhydroxyphenyl-triazine compositions and other compounds known to personshaving ordinary skill in the art, for example, TINUVIN™ 477DW,commercially available from BASF Corporation.

In some examples, the aqueous coating composition may optionally athickener. Thickeners may include hydroxyethyl cellulose;hydrophobically modified ethylene oxide urethane; processed attapulgite,a hydrated magnesium aluminosilicate; and other thickeners known topersons having ordinary skill in the art. For example, thickeners mayinclude CELLOSIZE™ QP-09-L and ACRYSOL™ RM-2020NPR, available from DowChemical Company; and ATTAGEL™ 50, available from BASF Corporation.Concentration of the optional thickener stabilizer in the aqueouscoating composition will be known to persons having ordinary skill inthe art or can be determined using standard methods.

Like the latex emulsion, the aqueous coating composition may be used tocoat substrates, e.g., as a primer coat or a topcoat. For example, theaqueous coating composition may be used to coat polymeric roofingmembranes, such as TPO membranes, EPDM rubber membranes, PVC membranes,or the like. The polymeric roofing membranes may be used as roofingmaterials. The aqueous coating composition may be applied directly tothe polymeric roofing membrane and preferably exhibits desirable dry andwet adhesion to the polymeric roofing membrane. For example, a coatingformed from the aqueous coating composition preferably exhibits a wetadhesion of greater than about 1 pound per linear inch, or greater thanabout 2 pounds per linear inch, or greater than about 4 pounds perlinear inch when tested using fabric embedded peel adhesion testing perASTM C794. In some examples, the latex-based coating 14 may be a primercoat and a topcoat 16 may be applied on the latex-based coating 14.

Although the latex emulsions and aqueous coating compositions have beendescribed as being used with roofing membranes, the latex emulsions andaqueous coating compositions may be used in other coating applications.For example, the latex emulsions and aqueous coating compositions may beused as tie layers for adhering other coating layers (such as otherlatexes), a coating for relatively low surface energy substrates (e.g.,substrates having a surface energy of less than about 40 dynes/cm, lessthan about 35 dynes/cm, less than about 30 dynes/cm, or less than about25 dynes/cm) (e.g., for low-surface-energy polymers such as PVC, EPDM,polyolefins, or the like), or the like.

Further, while the latex emulsions and aqueous coating compositions havebeen described as standalone compositions, in other examples, the latexemulsions and aqueous coating compositions may be used as additives toother latex emulsions or aqueous coating compositions. By including alatex copolymer formed from reactants comprising butyl methacrylate,wherein the reactants comprise at least 20 wt. % butyl methacrylate asan additive in another latex emulsion or aqueous coating composition,one or more of the advantages of latex emulsions or aqueous coatingcompositions described herein may be realized in combination withproperties contributed by the other latex emulsion or aqueous coatingcomposition.

Clause 1: A latex emulsion comprising: an aqueous carrier liquid; and alatex copolymer formed from reactants comprising butyl methacrylate,2-ethylhexyl methacrylate, VeoVa™ 10, or combinations thereof, whereinthe reactants comprise at least 20 wt. % of the butyl methacrylate,2-ethylhexyl methacrylate, VeoVa™ 10, or combinations thereof, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

The latex emulsion of clause 1, wherein a coating formed from the latexemulsion optionally and preferably exhibits a wet adhesion to athermoplastic polyolefin roofing membrane of greater than about 1 poundper linear inch when tested using fabric embedded peel adhesion testingper ASTM C794 at a coverage of about 80 ft²/gallon.

Clause 2: The latex emulsion of clause 1, wherein the reactants compriseat least 25 wt. % of the butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer.

Clause 3: The latex emulsion of clause 1, wherein the reactants compriseat least 30 wt. % of the butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer.

Clause 4: The latex emulsion of clause 1, wherein the reactants compriseat least 50 wt. % of the butyl methacrylate, 2-ethylhexyl methacrylate,VeoVa™ 10, or combinations thereof, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer.

Clause 5: The latex emulsion of any one of clauses 1 to 4, wherein thebutyl methacrylate, 2-ethylhexyl methacrylate, VeoVa™ 10, orcombinations thereof comprises n-butyl methacrylate or a mixture ofn-butyl methacrylate and 2-ethylhexyl methacrylate.

Clause 6: The latex emulsion of clause 1, wherein the reactants comprisebetween about 20 and about 50 wt. % of the butyl methacrylate,2-ethylhexyl methacrylate, VeoVa™ 10, or combinations thereof, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 7: An aqueous roof coating composition comprising: an aqueouscarrier liquid; a dispersant, a biocide, a fungicide, an UV stabilizer,a thickener, a wetting agent, a defoamer, a filler, a pigment orcolorant, or combinations thereof; and a latex copolymer formed fromreactants comprising a vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms, wherein the reactants comprise at least20 wt. % of the vinyl monomer having an alkyl group including between 2and 12 carbon atoms, based on the total weight of ethylenicallyunsaturated monomers used to make the latex copolymer, and wherein ahomopolymer formed from the vinyl monomer exhibits a glass transitiontemperature of between about −10° C. and about 30° C.;

The aqueous roof coating composition of clause 7, wherein a coatingformed from the coating composition optionally and preferably exhibits awet adhesion to a thermoplastic polyolefin roofing membrane of greaterthan about 1 pounds per linear inch when tested using fabric embeddedpeel adhesion testing per ASTM C794 at a coverage of about 80ft²/gallon.

Clause 8: A method comprising: reacting reactants comprising a vinylmonomer having an alkyl group including between 2 and 20 carbon atoms toform a latex emulsion including a latex copolymer, wherein the reactantscomprise at least 20 wt. % of the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer,wherein a homopolymer formed from the vinyl monomer exhibits a glasstransition temperature of between about −10° C. and about 30° C.

The method of clause 8, wherein a coating formed from the latex emulsionoptionally and preferably exhibits a wet adhesion to a thermoplasticpolyolefin roofing membrane of greater than about 1 pound per linearinch when tested using fabric embedded peel adhesion testing per ASTMC794 at a coverage of about 80 ft²/gallon.

Clause 9: The aqueous coating composition or method of clause 7 or 8,wherein the reactants comprise at least 25 wt. % of the vinyl monomerhaving an alkyl group including between 2 and 20 carbon atoms, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 10: The aqueous coating composition or method of clause 7 or 8,wherein the reactants comprise at least 30 wt. % of the vinyl monomerhaving an alkyl group including between 2 and 20 carbon atoms, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 11: The aqueous coating composition or method of clause 7 or 8,wherein the reactants comprise at least 50 wt. % of the vinyl monomerhaving an alkyl group including between 2 and 20 carbon atoms, based onthe total weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 12: The aqueous coating composition or method of any one ofclauses 7 to 11, wherein the reactants comprise between 20 and 50 wt. %of the vinyl monomer having an alkyl group including between 2 and 20carbon atoms, based on the total weight of ethylenically unsaturatedmonomers used to make the latex copolymer.

Clause 13: The aqueous coating composition or method of any one ofclauses 7 to 12, wherein the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms comprises a methacrylate havingan alkyl group including between 4 and 12 carbon atoms.

Clause 14: The aqueous coating composition or method of any one ofclauses 7 to 13, wherein the vinyl monomer having an alkyl groupincluding between 2 and 20 carbon atoms comprises laurel methacrylate,n-butyl methacrylate, iso-butyl methacrylate, t-butyl methacrylate,sec-butyl methacrylate, 2-ethylhexyl methacrylate, VeoVa™ 10, orcombinations thereof.

Clause 15: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 14, wherein the reactants further comprise: anethylenically unsaturated polar monomer; and a chain transfer agent.

Clause 16: The latex emulsion, aqueous coating composition, or method ofcause 15, wherein the reactants comprise at least about 0.1 part byweight of the ethylenically unsaturated polar monomer, based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 17: The latex emulsion, aqueous coating composition, or method ofclause 15, wherein the reactants comprise between about 0.1 and about 10wt. % of the ethylenically unsaturated polar monomer, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer.

Clause 18: The latex emulsion, aqueous coating composition, or method ofclause 15, wherein the reactants comprise between about 0.1 and about 5wt. % of the ethylenically unsaturated polar monomer, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer.

Clause 19: The latex emulsion, aqueous coating composition, or method ofany one of clauses 15 to 18, wherein the ethylenically unsaturated polarmonomer comprises an acid-functional ethylenically unsaturated monomer.

Clause 20: The latex emulsion, aqueous coating composition, or method ofclause 19, wherein the ethylenically unsaturated acid-functional monomercomprises acrylic acid, methacrylic acid, an at least partiallyneutralized acrylic acid, an at least partially neutralized methacrylicacid, or combinations thereof.

Clause 21: The latex emulsion, aqueous coating composition, or method ofany one of clauses 15 to 20, wherein the reactants comprise at leastabout 0.1 part by weight of the chain transfer agent, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer.

Clause 22: The latex emulsion, aqueous coating composition, or method ofany one of clauses 15 to 20, wherein the reactants comprise betweenabout 0.1 and about 1 part by weight of the chain transfer agent, basedon the total weight of ethylenically unsaturated monomers used to makethe latex copolymer.

Clause 23: The latex emulsion, aqueous coating composition, or method ofany one of clauses 15 to 22, wherein the chain transfer agent comprisesa mercaptan.

Clause 24: The latex emulsion, aqueous coating composition, or method ofclause 23, wherein the chain transfer agent comprises dodecyl mercaptan.

Clause 25: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 24, wherein the reactants further comprise asecond (meth)acrylate, wherein the second (meth)acrylate forms ahomopolymer that has a glass transition temperature that is less than−25° C.

Clause 26: The latex emulsion, aqueous coating composition, or method ofclause 25, wherein the second (meth)acrylate comprises an alkylacrylate.

Clause 27: The latex emulsion, aqueous coating composition, or method ofclause 26, wherein the second (meth)acrylate comprises 2-ethylhexylacrylate.

Clause 28: The latex emulsion, aqueous coating composition, or method ofany one of clauses 25 to 26, wherein the reactants comprise betweenabout 20 and about 80 wt. % of the second (meth)acrylate, based on thetotal weight of ethylenically unsaturated monomers used to make thelatex copolymer.

Clause 29: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 28, wherein the reactants further comprise aureido-functional monomer.

Clause 30: The latex emulsion, aqueous coating composition, or method ofclause 29, wherein the ureido-functional monomer comprises aureido-functional ethylenically unsaturated monomer.

Clause 31: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 30, wherein the latex copolymer exhibits avolume average particle size of between about 150 nm and about 550 nm.

Clause 32: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 31, wherein a coating formed from the latexemulsion or the aqueous coating composition exhibits a wet adhesion ofgreater than about 2 pounds per linear inch when tested using fabricembedded peel adhesion testing per ASTM C794.

Clause 33: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 32, wherein the latex copolymer exhibits a glasstransition temperature of less than about −10° C.

Clause 34: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 30, wherein the latex copolymer exhibits a glasstransition temperature of between about −50° C. and about −20° C.

Clause 35: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 34, wherein the latex copolymer exhibits a gelfraction of between 0% and about 5%, and wherein the solubilized portionof the latex copolymer exhibits a weight average molecular weight ofless than about 230,000 g/mol.

Clause 36: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 34, wherein the latex copolymer exhibits a gelfraction of between 0% and about 3.5%, and wherein the solubilizedportion of the latex copolymer exhibits a weight average molecularweight of between about 50,000 g/mol and about 200,000 g/mol.

Clause 37: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 36, wherein the reactants further comprise aseed latex.

Clause 38: The latex emulsion, aqueous coating composition, or method ofany one of clauses 1 to 37, comprising less than about 25 g/L volatileorganic compounds.

Clause 39: The aqueous coating composition of any one of clauses 7 to38, further comprising the biocide or the fungicide.

Clause 40: The aqueous coating composition of any one of clauses 7 to39, further comprising the UV stabilizer.

Clause 41: The aqueous coating composition of any one of clauses 7 to40, further comprising the thickener.

Clause 42: The aqueous coating composition of any one of clauses 7 to41, further comprising the wetting agent.

Clause 43: The aqueous coating composition of any one of clauses 7 to42, further comprising the defoamer.

Clause 44: The aqueous coating composition of any one of clauses 7 to43, further comprising the filler.

Clause 45: The aqueous coating composition of any one of clauses 7 to44, further comprising the pigment.

Clause 46: The aqueous coating composition of any one of clauses 7 to45, the coalescent.

Clause 47: A roofing system comprising: a polymeric roofing membrane;and a coating on a surface of the polymeric roofing membrane, whereinthe coating is formed from the latex emulsion or aqueous coatingcomposition of any one of clauses 1 to 45.

Clause 48: A method comprising: coating a polymeric roofing membranewith a coating formed from the latex emulsion or aqueous coatingcomposition of any one of clauses 1 to 45.

Clause 49: The roofing system or method of clause 47 or 48, wherein thepolymeric roofing membrane comprises a thermoplastic polyolefin,ethylene propylene diene monomer rubber, or poly(vinyl chloride) roofingmembrane.

Clause 50: The roofing system or method of any one of clauses 47 to 49,wherein the coating comprises a primer coat, further comprising a topcoat on the primer coat.

The disclosure will now be illustrated with reference to the followingnon-limiting examples.

EXAMPLES Latex Emulsion Synthesis Example 1

A monomer emulsion was made by first adding 330 g deionized water and46.7 g Rhodafac BS-715 (available from Solvay S.A., Neder-Over-Heembeek,Brussels, Belgium) to a beaker and agitating. Then, each of thefollowing was added: 33.6 g methacrylic acid, 22.8 g uriedo-functionalmethacrylic monomer, 5.0 g ammonium hydroxide (28%), 6.0 g dodecylmercaptan, 510 g 2-ethylhexyl acrylate, and 600 g n-butyl methacrylate.

To a 3-liter cylindrical flask was charged 400 grams (g) deionized waterand 40 g acrylic seed latex (30% non-volatile material). The flask wasfitted with an agitator and a flask head and placed in a water bathheated to 80° C. When the reaction flask had equilibrated at 80° C., 3.6g ammonium persulfate in 50 g of deionized water was added to the flaskand held for 5 minutes.

After the hold, the monomer emulsion was fed to the flask over thecourse of 3 hours. Simultaneously, a solution of 1.2 g ammoniumpersulfate in 70 g deionized water was fed to the reactor over 3 hours.Temperature of the flask was maintained at between 80° C. and 85° C.throughout the additions.

At the conclusion of the feeds, the flask was held at 80° C. for 30minutes before cooling to 60° C. and beginning redox post reaction. Forthe redox post reaction, an oxidizer solution was prepared by adding 1.7g t-butyl hydroperoxide to 20 g deionized water with agitation. Areducer solution was prepared by adding 1.2 g erythorbic acid to 20 gdeionized water with agitation. Following the post redox feed, the flaskwas cooled to 40° C., at which time 6.0 g ammonium hydroxide and 8.0 g1,2-benzisothiazolin-3-one (a biocide available under the tradedesignation Proxel™ AQ from Lonza Group, Basel, Switzerland) were addedto the flask.

The resulting latex emulsion had solids content of about 54.5%, a pH ofabout 7.6, a volume average particle size of about 197 nm, and ameasured T_(g) of about −26° C. Solids content was measured as follows:an aluminum weighing dish was weighted on an analytical balance and theweight recorded. Between about 0.5 g and about 0.75 g of latex was addedto weighing dish and the weight recorded. The initial pan weight wassubtracted from the pan plus latex weight to determine the weight oflatex in the pan. Between about 1 g and about 2 g of water was added tothe pan, and the pan was placed on a hot plate at 300° F. for 30minutes. The pan was then cooled and re-weighed. The initial weight ofthe pan (without latex) was subtracted from the weight of the driedweight plus pan to determine the weight of the dried latex. The weightof the dried latex was divided by the weight of the starting latex todetermine percent solids.

The volume average particle size may be determined using a Nanotrac WaveII particle size analyzer from Microtrac Inc., Montgomeryville, Pa.

The glass transition temperature was measured by air drying a sampleovernight and analyzing the dried sample on a Q2000 DSC from TAInstruments using a heat-cool-heat cycle from −75° C. to 150° C. at arate of 20° C. per minute. The glass transition temperature was measuredfrom the midpoint of the transition on the second heat cycle.

Aqueous Coating Composition Example 1

TABLE 1 Item Number Material Mass (g) 1 Water 154.90 2 Tamol ™ 165A11.00 3 Ammonium Hydroxide 3.00 4 Foamaster 111 5.00 5 R-960 60.00 6Duramite 400.00 7 Foamaster 111 5.00 8 Latex (about 55% solids) 490.00 9Texanol 6.74 10 Polyphase 663 10.87 11 Propylene Glycol 11.00 12Natrosol 250HBR 3.00 Total 1160.51

Tamol™ 165A is a hydrophobic copolymer pigment dispersant including apolycarboxylate ammonium salt, residual monomers, and water availablefrom Dow® Chemical Company, Midland, Mich. Foamaster® 111 is a non-ionicliquid defoamer for water-based paints and coatings, water-basedprinting inks, and latex adhesive systems available from BASF,Ludwigshafen, Germany. R-960 is a titanium dioxide pigment includingtitanium dioxide, alumina, and amorphous silica available from E. I. duPont de Nemours and Company, Wilmington, Del. under the tradedesignation DuPont® Ti-Pure® R-960. Duramite® is a medium particle sizemarble extender available from Imerys Carbonates, Paris, France.Texanol™ is an ester alcohol coalescent available from Eastman ChemicalCompany, Kingsport, Tenn. Polyphase® 663 is a zero VOC, water-baseddispersion of fungicides and an algaecide available from TroyCorporation, Florham Park, N.J. Natrosol™ 250 HB is ahydroxyethylcellulose available from Ashland Global Specialty Chemicals,Covington, Ky. In Aqueous Coating Composition Example 1, the latex wasthe latex emulsion prepared according to Synthesis Example 1.

Items 1-6 were added in order then mixed for 20 minutes under high shearusing a cowls blade. Items 7-10 were then added slowly. Items 11 and 12were mixed together then added. The final mixture was then mixed for anadditional 20 minutes with a good vortex.

Aqueous Coating Composition Comparative Example 1

In Aqueous Coating Composition Comparative Example 1, the latex was anall acrylic latex pressure sensitive adhesive available under the tradedesignation EPS 2113 from Engineered Polymer Solutions, Inc., Marengo,Illinois. Items 1-6 were added in order then mixed for 20 minutes underhigh shear using a cowls blade. Items 7-10 were then added slowly. Items11 and 12 were mixed together then added. The final mixture was thenmixed for an additional 20 minutes with a good vortex.

Peel Adhesion Testing

Aqueous coating compositions from Aqueous Coating Composition Example 1and Aqueous Coating Composition Comparative Example 1 were applied tosheets of virgin TPO (available under the trade designation UltraPly™TPO from Firestone, Nashville, Tenn.). The coating was applied at acoverage of about 80 ft²/gallon. Half of the coating composition masswas brushed onto the virgin TPO and a 4″ wide strip of non-wovenpolyester fabric available under the trade designation Henry 296ElastoTape® Repair Fabric from Henry Company, El Segundo, California wasembedded into the coating with one end left exposed to allow gripping bya clamp. The remaining coating composition mass was then brushed ontothe embedded polyester fabric. The resulting coating was continuous witha generally consistent thickness.

Samples were dried under ambient conditions for 14 days. Dry adhesionwas then measured using an MTS Insight® Electromechanical TestingSystem. The fabric was gripped in one clamp of the MTS Insight®Electromechanical Testing System and the virgin TPO sheet in the otherclip. The pulling rate was 2 inches per minute and 2 inches of thesamples were tested. The results are shown in Table 2.

TABLE 2 Dry Adhesion (pounds per linear Sample inch) Aqueous CoatingComposition 0.475 Comparative Example 1 Aqueous Coating Composition 1.25Example 1

After dry adhesion testing, the samples were then immersed in water for7 days. Wet adhesion was then tested according to ASTM C794 using an MTSInsight® Electromechanical Testing System. The fabric was gripped in oneclamp of the MTS Insight® Electromechanical Testing System and thevirgin TPO sheet in the other clip. The pulling rate was 2 inches perminute and 2 inches of the samples were tested. The results are shown inTable 3.

TABLE 3 Wet Adhesion (pounds per linear Sample inch) Aqueous CoatingComposition 0 Comparative Example 1 Aqueous Coating Composition 3.6Example 1

Latex Emulsion Synthesis Example 2

A series of samples were prepared according to Latex Emulsion SynthesisExample 1, except the 2-ethylhexyl acrylate and n-butyl methacrylatewere replaced with the monomers (and monomer ratios) shown in Table 4.The latexes were then formulated consistent with Aqueous CoatingComposition Example 1. Peel testing was conducted consistent with thetest method set forth above.

TABLE 4 Average Peel Sample Monomers Strength (lbf/in) 1 416 g n-butylmethacrylate 4.6845 610 g butyl acrylate 2 200 g n-butyl methacrylate2.0905 111 g methyl methacrylate 250 g 2-ethylhexyl methacrylate 466 gethylhexyl acrylate 3 555 g 2-ethylhexyl methacrylate 1.7085 471 gethylhexyl acrylate 4 416 g 2-ethylhexyl methacrylate 2.042 610.5 gbutyl acrylate 5 410 g VeoVa ™ 10 2.476 472 g ethylhexyl acrylate 144 gmethyl methacrylate

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A composition comprising: an aqueous carrierliquid; and a latex copolymer formed from reactants comprising a chaintransfer agent and a vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms, wherein the reactants comprise between 20wt. % and 60 wt. % of the vinyl monomer having an alkyl group includingbetween 2 and 12 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer, andwherein a homopolymer formed from the vinyl monomer exhibits a glasstransition temperature of between about −10° C. and about 30° C.;wherein the latex copolymer exhibits a gel fraction of between 0% andabout 10%, and wherein the solubilized portion of the latex copolymerexhibits a weight average molecular weight of less than about 230,000g/mol; wherein the latex copolymer exhibits a glass transitiontemperature of between about −50 ° C. and about −15° C.; and wherein acoating formed from the composition exhibits a wet adhesion to athermoplastic polyolefin roofing membrane of greater than about 1 poundper linear inch when tested using fabric embedded peel adhesion testingper ASTM D903 at a coverage of about 80 ft²/gallon.
 2. The compositionof claim 1, wherein the vinyl monomer comprises butyl methacrylate,ethylhexyl methacrylate, a vinyl ester of neodecanoic acid, orcombinations thereof.
 3. The composition of claim 2, wherein the butylmethacrylate, ethylhexyl methacrylate, the vinyl ester of neodecanoicacid, or combinations thereof comprises n-butyl methacrylate or amixture of n-butyl methacrylate and ethylhexyl methacrylate.
 4. Thecomposition of claim 1, further comprising a dispersant, a biocide, afungicide, an UV stabilizer, a thickener, a wetting agent, a defoamer, afiller, a pigment or colorant, or combinations thereof.
 5. Thecomposition of claim 1, wherein the reactants comprise between 30 wt. %and 60 wt. % of the vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. 6.The composition of claim 1, wherein the reactants comprise between 20and 50 wt. % of the vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer. 7.The composition of claim 1, wherein the reactants further comprise: anethylenically unsaturated polar monomer.
 8. The composition of claim 7,wherein the chain transfer agent comprises dodecyl mercaptan.
 9. Thecomposition of claim 1, wherein the reactants further comprise a second(meth)acrylate, wherein the second (meth)acrylate forms a homopolymerthat has a glass transition temperature that is less than −25° C. 10.The composition of claim 9, wherein the second (meth)acrylate comprises2-ethylhexyl acrylate.
 11. The composition of claim 1, wherein thereactants further comprise a ureido-functional ethylenically unsaturatedmonomer.
 12. The composition of claim 1, wherein the coating formed fromthe composition exhibits a wet adhesion of greater than about 2 poundsper linear inch when tested using fabric embedded peel adhesion testingper ASTM D903.
 13. The composition of claim 1, wherein the latexcopolymer exhibits a glass transition temperature of between about −50°C. and about −20° C.
 14. A roofing system comprising: a polymericroofing membrane; and a coating on a surface of the polymeric roofingmembrane, wherein the coating is formed from a composition comprising:an aqueous carrier liquid; and a latex copolymer formed from reactantscomprising a chain transfer agent and a vinyl monomer having an alkylgroup including between 2 and 20 carbon atoms, wherein the reactantscomprise between 20 wt. % and 60 wt. % of the vinyl monomer having analkyl group including between 2 and 12 carbon atoms, based on the totalweight of ethylenically unsaturated monomers used to make the latexcopolymer, and wherein a homopolymer formed from the vinyl monomerexhibits a glass transition temperature of between about −10° C. andabout 30° C.; wherein the latex copolymer exhibits a glass transitiontemperature of between about −50° C. and about −15° C.; and wherein acoating formed from the coating composition exhibits a wet adhesion to athermoplastic polyolefin roofing membrane of greater than about 1 poundper linear inch when tested using fabric embedded peel adhesion testingper ASTM D903 at a coverage of about 80 ft²/gallon.
 15. The roofingsystem of claim 14, wherein the polymeric roofing membrane comprises athermoplastic polyolefin, ethylene propylene diene monomer rubber, orpoly(vinyl chloride) roofing membrane.
 16. The roofing system of claim14, wherein the coating comprises a primer coat, further comprising atop coat on the primer coat.
 17. A method comprising: reacting reactantscomprising a chain transfer agent and a vinyl monomer having an alkylgroup including between 2 and 20 carbon atoms to form a latex emulsionincluding a latex copolymer, wherein the reactants comprise between 20wt. % and 60 wt. % of the vinyl monomer having an alkyl group includingbetween 2 and 20 carbon atoms, based on the total weight ofethylenically unsaturated monomers used to make the latex copolymer,wherein a homopolymer formed from the vinyl monomer exhibits a glasstransition temperature of between about −10° C. and about 30° C.,wherein the latex copolymer exhibits a gel fraction of between 0% andabout 5%, and wherein the solubilized portion of the latex copolymerexhibits a weight average molecular weight of less than about 230,000g/mol, wherein the latex copolymer exhibits a glass transitiontemperature of between about −50° C., and about −15° C., and wherein acoating formed from the latex emulsion exhibits a wet adhesion to athermoplastic polyolefin roofing membrane of greater than about 1 poundper linear inch when tested using fabric embedded peel adhesion testingper ASTM D903 at a coverage of about 80 ft²/gallon.
 18. The method ofclaim 17, wherein the vinyl monomer comprises butyl methacrylate,ethylhexyl methacrylate, a vinyl ester of neodecanoic acid, orcombinations thereof.
 19. The method of claim 18, wherein the butylmethacrylate, ethylhexyl methacrylate, the vinyl ester of neodecanoicacid, or combinations thereof comprises n-butyl methacrylate or amixture of n-butyl methacrylate and ethylhexyl methacrylate.